Star Trek: 10 Disturbing Side Character Backstories

Doctor Lewis Zimmerman was the renowned holographic specialist who created Voyager's Emergency Medical Hologram (The Doctor). The Doctor frequently mentioned Dr. Zimmerman, referring to him almost as a sort of father-figure. Eventually he even got the chance to meet him in person in the episode Life Line.

When we meet Dr. Zimmerman in this episode, it's clear that he's unhappy with life. He shuns interaction with other people in favour of holograms of his own creation. He was mostly upset because he was dying, but he gave up hope because he was unsatisfied with his life's work.

The EMH Mark I was revolutionary when it was first invented, so much so that Dr. Zimmerman based its design off of his own appearance. Unfortunately for Lewis, technology rapidly advanced and eventually it was time to create the EMH Mark II. When the Mark I's were phased out, they weren't simply destroyed, but instead sent to mine ore for the Federation. All across the quadrant, there were highly intelligent holograms with the voice and face of Doctor Zimmerman drudging through mines, working without rest as expendable pawns.

This resentment towards the EMH Mark I's is why Lewis originally rejected The Doctor's help.